According to plastic injection molding techniques, a piece to be molded is formed around a male body part within the mold apparatus from which the piece must be ejected to allow the molding of further pieces. At the present time mechanical stripper ring ejectors are most widely accepted in the molding field. However, it has recently been discovered that gas blow-off systems provide advantages such as reducing core shift problems resulting from mechanical pressure which causes thickness differential problems in thin walled containers using these stripper ring mechanical ejectors. However, with gas blow-off if there is overflow of the mold material, known in the industry as flashing, then this overflow can block the vents used in the blow-off requiring the mold apparatus to be shut down and cleaned out, which may take many hours of down time.